Out
of the boat, a gasoline inboard joined to a stern drive has a zoomorphic
profile. Powerful V-8 above, sleek drive below, it's like a barrel-chested
merman in Neptune's mythological honor guard. However (and despite
that overwrought metaphor), when you first lay eyes on MerCruiser's
new 8.1S Horizon (370 hp) or 8.1S HO (420 hp), the first thing you notice
is a nifty little blue hand pump mounted on the heat exchanger. It's
part of the new air pressure-actuated raw-water draining system, a convenience
designed for those weeks in the spring and fall when nights are freezing
cold but daytime weather is pleasant enough to encourage cruising. Pump
air into a pair of fittings located near the top of the engine, and
within moments valves below open to drain the entire raw-water system.
Release the pressure with the pull of a pin, and the valves close again.
Boaters reluctant to call a halt to their seasons at the first hint
of cold weather will no doubt find this means of quick, if somewhat
abridged, winterization attractive. For those hot months of the high
season, a water-cooled fuel system combines with a water/fuel separator
to forestall vapor lock.

MerCruiser has also
designed a special exhaust system for these engines. Aluminum manifolds
and stainless steel elbows, both ceramic coated and painted using
the electro-deposition process (in which paint is given one electrical
charge and the object to be painted the opposite), reduce the weight
of the system by 65 percent. Cooling water that used to travel directly
between the manifolds and elbows now bypasses a dry joint, so the
occasional "weeping" at this juncture should be a thing
of the past.

Both the 8.1S Horizon
and 8.1S HO are also equipped with an electronic engine-control module
made by Motorola. Built into this unit is the PCM 555 processor, the
heart of MerCruiser's new SmartCraft system. Thus both the models
are SmartCraft-compatible. Available prerigged from a number of boatbuilders,
SmartCraft in its most comprehensive version, the SC5000 System
View, integrates engine data such as fuel flow, rpm, and temperature
with GPS and depthsounder readouts, water, fuel, and waste tank levels--you
name it--all on a single LCD screen. In all, the processor gathers
information on 64 internal functions while keeping tabs on numerous
sensors installed throughout the vessel. Big Brother has indeed gone
to sea, but you still call the shots: Through the same SC5000 screen
you will eventually control trim tabs and bilge ventilators.

Whether or not you
take advantage of this remarkable technology, MerCruiser backs these
engines with a standard one-year warranty and offers extended coverage
for two, three, or four years.

Boaters interested
in cruising at only a slightly quicker pace will be intrigued by another
new engine from MerCruiser, one not based on the new GM 8.1. The company
enlarged its existing GM 5.7-liter V-8 to 6.2-liters, thanks to a
new crankshaft that offers a longer stroke and reconfigured rods and
pistons. The new MX 6.2 MPI puts out 320 hp at the prop, produces
more torque, and shares many of the performance-enhancing features
of the 8.1s, including multiport fuel injection and a billet-steel,
special-profile camshaft. Also like the 8.1s, the 6.2 can be mounted
as a conventional inboard or with a stern drive.